Theoretical investigations of spin splittings in asymmetric AlSb/InAs/GaSb heterostructures and the possibility of electric field induced magnetization

Cartoixà, Xavier; Ting, David Z.; Daniel, Erik S.; McGill, T. C.

doi:10.1006/spmi.2002.1021

Cited by 18 publications

(15 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, nonlinear effects also become more pronounced with increasing W. A further consideration is that ␣ R tends to be larger in narrower-gap materials, [16][17][18] although nonlinearities again become more significant. Combining with the Rashba expression given above, the cancellation condition is ␣ R ϰ −1 / ͱ 3͗k n 2 ͘.…”

Section: Formalismmentioning

confidence: 99%

Spin-relaxation suppression by compensation of bulk and structural inversion asymmetries in [111]-oriented quantum wells

Vurgaftman

Meyer

2005

Journal of Applied Physics

View full text Add to dashboard Cite

Experimental and theoretical study for InAs quantum dashes-in-a-step-well structure on (001)-oriented InP substrateWe investigate the feasibility of compensating the bulk inversion asymmetry in a ͓111͔-oriented quantum well with the Rashba structure inversion asymmetry that has precisely the same functional form. The resulting cancellation is found to provide a promising means for strongly suppressing the spin-relaxation rate associated with the D'yakonov-Perel' ͑DP͒ mechanism. We discuss a detailed numerical study of the spin splitting in a suitable InAlAs/ InGaAs/ InP quantum well grown on a ͓111͔ InP substrate, for which an external electric field is used to fine tune the asymmetry. We show that the DP spin-relaxation rate can be suppressed by nearly an order of magnitude at room temperature and by a factor of 2000 at 10 K.

show abstract

Section: Formalismmentioning

confidence: 99%

Spin-relaxation suppression by compensation of bulk and structural inversion asymmetries in [111]-oriented quantum wells

Vurgaftman

Meyer

2005

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…In particular, the issue of creating spin polarization of carriers in nonmagnetic semiconductors with spin-orbit coupling using only electric fields has caused a flurry of theoretical and experimental activity [4,5,6,7,8,9,10,11,12,13,14,15,16]. Two kinds of theories of spin-polarization under the action of an electric field have been put forward.…”

mentioning

confidence: 99%

Spin splitting and spin current in strained bulk semiconductors

Bernevig

Zhang

2005

Phys. Rev. B

View full text Add to dashboard Cite

We present a theory for two recent experiments in bulk strained semiconductors [1,2] and show that a new, previously overlooked, strain spin-orbit coupling term may play a fundamental role. We propose simple experiments that could clarify the origin of strain-induced spin-orbit coupling terms in inversion asymmetric semiconductors. We predict that a uniform magnetization parallel to the electric field will be induced in the samples studied in [1,2] for specific directions of the applied electric field. We also propose special geometries to detect spin currents in strained semiconductors. 72.15. Gd Spin manipulation in semiconductors has seen remarkable theoretical and experimental interest in recent years with the advent of spin-electronics and with the realization that strong spin-orbit coupling in certain materials can influence the transport of carriers in so-called spintronics devices [3]. In particular, the issue of creating spin polarization of carriers in nonmagnetic semiconductors with spin-orbit coupling using only electric fields has caused a flurry of theoretical and experimental activity [4,5,6,7,8,9,10,11,12,13,14,15,16]. Two kinds of theories of spin-polarization under the action of an electric field have been put forward. The first kind, dating back since the mid 1980's [9], predicts the existence of a spatially homogeneous net spin polarization perpendicular to the applied electric current in two dimensional samples with spin-orbit interaction. This effect is dissipative and has been recently observed experimentally [17]. There also exist two very recent [4,5] theories predicting non-dissipative, intrinsic spin currents with the spin polarization and flow direction perpendicular to each other and to the electric field. This effect does not create a bulk magnetization but, if observed, can be used for spin injection, and its validity is being experimentally tested at the present time. One of the theories [5] predicts a spin current polarized out of plane and flowing perpendicular to the in-plane electric field applied on a 2-dimensional semiconductor sample exhibiting Rashba spin-orbit coupling. As long as the Rashba spin splitting is large enough, the spin conductivity is 'universal' (e/8π ) in the sense that it does not depend on the value of the coupling. The other effect [4] appears in the valence band of the bulk samples and is proportional to the spin-orbit splitting of the valence bands (to the difference between the Fermi momenta of the heavy and light-hole bands).In the first part of this letter we analyze the theory behind two recent experiments in bulk strained semiconductors [1,2] where an electric-field-induced uniform homogeneous spin polarization upon an applied electric field is observed. We make the case that the observed spinsplitting (whose origin is puzzling) and spin polarization is due to a previously overlooked strain-spin-splitting term, and propose easy experimental checks of our theory.In the second part of this letter we predict the appearance of an intrinsic spin po...

show abstract

“…The computed α B I A for this structure is about half of the predicted Rashba coefficient for some asymmetric structures [26,32] where only SIA contributions are taken into account. This indicates that situations may arise where BIA effects need to be carefully studied before neglecting them in a calculation.…”

Section: Resultsmentioning

confidence: 82%

An efficient multiband envelope function approximation method for spintronics

2003

View full text Add to dashboard Cite

We have developed an eight-band finite-difference envelope function approximation model capable of reproducing in almost all situations the true D 2d or C 2v symmetry of [001] grown zinc-blende heterostructures. We have used our model to study the relative contributions of the bulk inversion asymmetry (BIA) and structural inversion asymmetry to the spin splitting in the conduction band of asymmetric AlSb/GaSb/InAs/AlSb quantum wells, and clarify apparently contradictory statements about the relative magnitude of the two contributions. We show that, in the system under study, the inclusion of BIA effects changes considerably the angular dependence and the magnitude of the splitting. We also investigate how BIA changes the transmission properties of a resonant tunnelling structure.

show abstract

Theoretical investigations of spin splittings in asymmetric AlSb/InAs/GaSb heterostructures and the possibility of electric field induced magnetization

Cited by 18 publications

References 34 publications

Spin-relaxation suppression by compensation of bulk and structural inversion asymmetries in [111]-oriented quantum wells

Spin-relaxation suppression by compensation of bulk and structural inversion asymmetries in [111]-oriented quantum wells

Spin splitting and spin current in strained bulk semiconductors

An efficient multiband envelope function approximation method for spintronics

Contact Info

Product

Resources

About